The successful development of reliable electronic components and circuits and the desire for increased security has created an interest in the development of identification systems which employ user carried devices such as cards and the like to gain access to otherwise secure information, equipment and/or locations.
In one proposed identification system, the user carried device includes a miniature fixed value resistor and sensor means for determining if the resistor has the proper value. The miniature resistor in the user carried device has leads which make sliding electrical contact with stationary contacts of the identification system when the carrier device is inserted into an appropriate opening. Access is permitted if the resistor has the correct value and denied if it has the wrong value. For such application and other applications, there is a need for small packaged electronic components such as fixed value resistors, which have durable leads which can operate for thousands of cycles and which are an integral part of the packaged component.
There is also a need in other applications for very small fixed value resistors especially those with a length/width aspect ratio of 1 or less. The standard physical sizes of resistors which have been established are primarily based on or determined by the maximum power rating of the given device and the basic technology used in its manufacture. As a result, most of the commonly available resistors are based on a cylindrical geometry with axial leads in which the length/width aspect ratio is greater than 1. This symmetrical geometry is used because of the symmetry considerations and to maximize the electrical length of the resist filament.
In the past, it has been difficult to commercially manufacture very small packaged resistors or resistors having small lenght/width aspect ratio using known resistor preparation technology such as carbon composition, carbon film, metal film or metal glaze in the symmetrical geometry. The commonly used resistor preparation technologies can easily be adapted to make resistors larger than those which are normally encountered. However, problems are encountered when one tries to make very small resistors with a length/width aspect ratio which is less than 1 or with unusual lead or terminal configurations.